The present invention relates to a device incorporated in a bidirectional CATV (Cable Television) system for reducing the noise of up-going signals and, more particularly, to a device for reducing the noise of up-going signals introduced at subscriber stations.
It is a common practice with a noise reducing device of the type described to cause the central station to turn on and off a line switch of a repeater every time noise is introduced in an up-going signal, since a down-going channel is constantly connected. The problem is, therefore, that the place where noise is introduced cannot be rapidly located, slowing down the recovery. Moreover, since the up-going signal is turned off by a repeater, the central station has to interrupt communication with a plurality of terminals even when noise is introduced at a single location. In addition, the control relying on a switch built in a repeater is not practicable without resorting to complicated and expensive circuitry.